The invention relates to a method for setting up a wastewater pumping station in a wastewater shaft.
According to the method, at least one solids collecting tank for wastewater which is guided through the same and is loaded with solids, a liquid collecting tank for the wastewater which has been rid of solids and has been pretreated in the solids collecting tank and a pump which is assigned to the solids collecting tank for emptying the liquid collecting tank via the solids collecting tank are produced as separate assemblies for the most part in each case, i.e., the solids collecting tank, the liquid collecting tank and the pump are able to be produced as three separate assemblies. It is also possible, however, to condense for example the pump and the solids collecting tank to form one assembly. Then, with the liquid collecting tank as a further assembly, a total of two assemblies are realized.
Wastewater pumping stations are generally installed into a wastewater shaft and are utilized to pump wastewater, which has collected at the bottom of a wastewater storage chamber, to a certain level. Further treatment is then effected in the majority of cases in a wastewater treatment plant. Large pumps are frequently used in practice for this purpose, however, the pumps typically have low efficiencies.
A wastewater pumping station where solids are separated from the conveying medium, as a rule the wastewater, is employed in the case of the generic method according to European patent document no. EP 1 108 822 A1. Only after separation does the wastewater, which has been pretreated in such a manner, enter a regularly used pump. The solids collecting tank which is connected upstream of the pump takes care of the described separation of the solids from the wastewater. A separating screen, by which ideally the solids are held back, is typically provided in the interior of the solids collecting tank for this purpose. As a result, pretreated wastewater leaves the solids collecting tank and can be transferred into the liquid collecting tank which is connected downstream of the solids collecting tank.
In the case of the wastewater pumping stations realized in practice, the procedure is generally such that the wastewater shaft, the solids collecting tank, the liquid collecting tank and the pump are all prefabricated and installed at the installation site. For this purpose, European patent document no. EP 1 108 822 A1 proposes in one variant that the liquid collecting tank and the wastewater shaft which receives the wastewater pumping station are produced from plastics material, with the shaft bottom simultaneously forming the bottom of the liquid collecting tank. Industrial prefabrication of the entire wastewater pumping station is able to be realized in this manner, which simplifies installation on site.
However, wastewater shafts produced from plastics material can often not cope with the static and dynamic loads prevailing on site or cannot cope with them in the long term. Wastewater shafts produced from concrete are increasingly used in this context for this reason. This implies production of the wastewater shaft prior to installation of the actual wastewater pumping station because the transport of wastewater shafts produced from concrete is ultimately prohibited for reasons of cost. In this context, European patent document no. EP 1 108 822 A1 already proposes that the solids collecting tank and the liquid collecting tank can be realized as assemblies which are separate from one another by providing a modular construction unit.
Such separate assemblies provide advantages in maintenance and construction because maintenance jobs and also repair jobs can be performed separately from one another on the aforementioned construction elements in the wastewater shaft. This has proved its worth in principle.
However, the handling of the component parts for the wastewater pumping station in particular during transport over large distances requires improvement. This is because individual component parts of the wastewater pumping station such as, in particular, the liquid collecting tank, are particularly bulky and heavy. This is even more valid when, as in the further prior art according to German patent document no. DE 33 33 883 A1, a tank, which is used to receive a pump for a wastewater pumping station, is produced from concrete. Factory-based series production is to be made possible as a result. However, the volumes and weights looked at are exorbitant such that in practice it is not possible to transport the known tanks over long distances. The invention aims to create a remedy here.
The technical problem underlying the invention is to develop further such a method for setting up a wastewater pumping station in a wastewater shaft such that a clear reduction in costs is seen in particular for transport and at the same time the setting up of new stations as well as the renovation of older stations is made easily possible.
To solve said technical problem, a generic method for setting up a wastewater pumping station in a wastewater shaft within the framework of the invention is characterized in that at least the solids collecting tank and the pump are prefabricated as a construction unit and the relevant construction unit is combined with the liquid collecting tank, which is already present on site, in the course of the installation in the wastewater shaft, which is also already present on site.
Within the framework of the invention, the wastewater pumping station is consciously separated into component parts that are present on site and component parts that are prefabricated by the manufacturer. In this case, the component parts that are present on site include not only the wastewater shaft, as has already been publicized in practice and described in the prior art, but also according to the invention said component parts that are present on site also additionally include the liquid collecting tank.
Obviously, it is also possible for several liquid collecting tanks to be present in the wastewater shaft or realized on site if required. In addition, it is within the framework of the invention to combine, for example, several construction units produced in each case from the solids collecting tank and the pump with a liquid collecting tank or even several of said liquid collecting tanks as described. As a result, a parallel operation of, for example, two construction units can be realized in order to obtain, for example, increases in pressure and/or quantities overall. Over and above this, it is also possible on the part of the manufacturer to combine, for example, one solids collecting tank with two or more pumps and likewise several solids collecting tanks with one pump to form the prefabricated construction unit. In each case, the transport costs are significantly reduced because the liquid collecting tanks are typically designed to be bulky and heavy and according to the invention are already realized on site.
To this is added that possible problems with the compressive strength of the liquid collecting tank or also adaptations on site when installing the liquid collecting tank are non-existent. Apart from this, the investment costs are reduced or can be split in terms of time and function. To this is added that, according to the described method, it is possible both to renovate existing installations and produce new installations. This is because, to do this, all that is necessary is to adapt the construction unit to the liquid collecting tank.
As a result of the separation between the component parts that are present on site and the component parts that are prefabricated (by the manufacturer) when realizing the wastewater pumping station according to the invention, one or several interfaces have ultimately to be worked with. It is provided here within the framework of the invention that the construction unit which is produced from at least the solids collecting tank and the at least one pump, on the one hand, and the liquid collecting tank, on the other hand, are coupled together on site by at least one interface. Said interface can be mounted in or on a partition wall.
The partition wall addressed is arranged, as a rule, in the wastewater shaft. The wastewater shaft is able to be divided into a dry chamber and a wet chamber by the partition wall. The construction unit which is produced from the solids collecting tank and the pump is typically placed in the dry chamber. In contrast, the function of the wet chamber is for receiving the liquid collecting tank that is provided there.
As the construction unit which is produced from at least the solids collecting tank and the pump is designed in a particularly compact manner within the framework of the invention, transport costs can be reduced and, compared to the prior art, it is possible to work with a clearly reduced transport volume. This presupposes at the same time that the liquid collecting tank is produced on site in the interior of the wastewater shaft according to corresponding requirements and in particular the interface between the construction unit and the liquid collecting tank fulfills and also is able to fulfill its function. Effectively, in the simplest case said interface can be a tube coupling, a flange adapter and, where applicable, a feedthrough for the partition wall. This is because, as a rule, the pump is connected to the liquid collecting tank on the suction side by the interface.
In this case, it is also possible over and above this to pass an intake for the construction unit through the liquid collecting tank. The wastewater to be pumped is supplied to the solids collecting tank by said intake. As, consequently, the intake is expediently passed through the liquid collecting tank and also through the partition wall in the interior of the wastewater shaft, it is once again necessary to work with an interface to the relevant solids collecting tank at this location.
On account of said design, it is possible to design the wastewater shaft in a more compact manner and with a smaller shaft height than previously. This is because, as a result of the smaller height of the intake which is passed through the liquid collecting tank compared to the prior art, where the intake is arranged above the liquid collecting tank, the available volume in the wastewater shaft is able to be utilized in an optimum manner.
In addition, mounting and arranging the liquid collecting tank directly in the wastewater shaft provides the possibility of the installation height of the construction unit which is produced from the solids collecting tank and the pump being reduced further. This is because it is possible to integrate a connecting line from the pump to the solids collecting tank and an outlet, which is realized as a by-pass, into the solids collecting tank. The design, in this case, may be comparable to that already described in International patent document no. WO 2010/025852 A1.
It is quite particularly preferred when the liquid collecting tank is integrated into the wastewater shaft on site. That is to say, in the case of the on-site production of, on the one hand, the wastewater shaft and, on the other hand, the liquid collecting tank, the procedure is such that the liquid collecting tank is designed as part of or a component part of the wastewater shaft. In this context, it is recommended that the liquid collecting tank and the wastewater shaft are produced for the most part from uniform materials.
Effectively, such a design corresponds for the most part to the liquid collecting tank and the wastewater shaft comprising several common walls. For example, the liquid collecting tank can be defined in the interior of the wastewater shaft by the already addressed partition wall such that the liquid collecting tank covers simply part of the floor of the wastewater shaft. The liquid collecting tank is consequently defined in the wastewater shaft as an open tub which is able to be closed at the head end by a removable cover.
In this way, the partition wall carries out its dividing function in an automatic manner. This is because the wet chamber is defined in the region of the liquid collecting tank, whereas the dry chamber is available for the arrangement of the construction unit on the other side of the wet chamber and of the partition wall. The modular solids collecting tank and also the at least one pump, both of which are consequently accessible in a particularly simple manner for maintenance and cleaning purposes, are situated in the dry chamber, even during operation.
The construction unit which is produced from at least the solids collecting tank and the pump can be produced from different materials. Metal, plastics material and even concrete have proved possible here, combinations also being included. Comparable materials can also be used for the wastewater shaft and, where applicable, the liquid collecting tank. Concrete, metal, plastics material or combinations can be worked with in this case, too. An object of the invention is also a wastewater pumping station and is set up in a wastewater shaft in particular according to the previously described method.
A method for constructing or setting up a wastewater pumping station in the wastewater shaft and an associated wastewater pumping station, both of which as a result provide particular advantages with regard to costs and logistics, are described. As a result of the modular design of individual component parts and of the separation into component parts which are present on site and component parts which are prefabricated (by the manufacturer), it is possible not only to equip new plants in a corresponding manner but also the renovation of older plants is successful in a particularly advantageous manner. This is because, in this connection, it is only a question of making the wastewater shaft available on site in connection with the liquid collecting tank. In addition, the at least one interface between the liquid collecting tank and the at least one solids collecting tank has to correspond to the requirements.
As a result of the liquid collecting tank being present on site or being realized on site before the construction unit (which is produced from the solids collecting tank and the pump) is installed into the wastewater shaft, it is possible to pass the intake for the construction unit through the liquid collecting tank and also to realize it already on site. In this case, another additional interface, to which the intake is connected, is then necessary between the intake, on the one hand, and the solids collecting tank on the other hand. Low intake heights can be realized as a result and overall the wastewater pumping station can be designed in a particularly compact manner and the shaft height of the wastewater shaft can be reduced to a minimum.
Another advantage to be named is that as a result of the compact design, it is also possible to work with few individual parts and small installation openings in the wastewater shaft, which reduces the costs even further. At the same time, repair and maintenance are simplified. These are the essential advantages.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.